Noisy Autohelm - ST1000+

[voodooacrobat]

A have a new Raymarine Autohelm ST1000+ that sometimes makes a loud squealing noise. Sounds like there's a dolphin in the cockpit! It doesn't always happen, and it appears to be working in all other respects. It doesn't matter what the sea state is or how much load is on the unit. It just sometimes - and not often - squeals. Damned annoying.

Before I send it back to Raymarine (it's under warranty), does anyone know if this is just a lubrication problem that I can solve myself? I singlehand a lot and I've grown to depend on the thing. I'd hate to be without it while it's serviced.

Thanks in advance,

Mark